More Tornado jets have taken off from Norfolk to join the UN-backed force protecting Libya's population from Colonel Gaddafi, it emerged last night.

Marham Tornado jets have been flying 'armed reconnaissance missions' to safeguard Libya's population from Col Gaddafi's forces, since the first wave of aircraft arrived at their forward operating base in southern Italy on Monday.

Late last night, the Chief of Defence Staff's spokesman Major General John Lorimer said: 'A further four GR4 Tornados left RAF Marham in Norfolk earlier this afternoon to conduct further air reconnaissance missions over Libya as part of Operation Ellamy.

'These Tornados have now landed at Gioia del Colle and will stand ready to assist as required.'

In an address shown on Libyan state television, a defiant Gaddafi said: 'In the short term, we'll beat them, in the long term, we'll beat them.'

The Libyan leader was said to have delivered the message to supporters at his residential compound near the capital Tripoli which was hit by an allied cruise missile on Sunday.

It came as US commanders warned pro-Gaddafi forces could expect further attacks, amid growing questions at home and abroad over both the leadership of the mission - dubbed Operation Ellamy - and its longer-term objectives.

Yesterday, defence sources said Marham aircraft were using their advanced aerial imaging equipment to survey activity on the ground.

Similar technology has been used by the jets to protect ground troops in Afghanistan, using cameras so sensitive they can spot whether the ground has been disturbed.

At a briefing in London yesterday, Maj Gen Lorimer said a number of aircraft had left Marham on Monday afternoon.

Detailing their mission, he added: 'Unlike their previous sorties on Saturday and Sunday, which were focused on Libyan military command and control facilities and air defence infrastructure, their mission yesterday was an armed reconnaissance sortie to protect directly the civilian population from attacks by Col Gaddafi's ground forces.

'With their state of the art Litening targetting pods and a variety of precision guided munitions, the Tornados are very well equipped to identify any emerging threats on the ground and deliver a dynamic and effective response.

'Again, the GR4s were supported by VC-10 and Tristar tankers, and on completion of their mission, the Tornados joined the Typhoons forward based at Gioia del Colle.

'This work is obviously in addition to their long-standing tasks supporting operations in Afghanistan and elsewhere around the world.'

Maj Gen lorimer said the operation was having 'a real effect' on Col Gaddafi's forces.

'As we enter the fourth day of Operation Ellamy, we are still conducting detailed assessment of the effects of military action against specific military targets,' he said.

'In any case, you will understand that at this time it would not be wise to disclose to Colonel Gaddafi precisely how well we believe we have performed in degrading his command and control network and his integrated air defence system.

'But on a broader level, we have the best possible indication that this operation is having a very real effect; namely the protection of Benghazi from Colonel Gaddafi's forces.

'Last Friday, you will recall that regime troops were on the outskirts of Benghazi, the second largest city in Libya and home to more than 670,000 civilians. Colonel Gaddafi vowed that his men would be going from house to house, room to room, to burn out the opposition. Libyan troops were reportedly committing atrocities in outlying areas of the city.

'The military intervention to enforce UNSCR 1973 has stopped that attack in its tracks. That is not to say that all threat to innocent life in and around Benghazi, or other cities for that matter, has been wholly removed. It has not. But the very fact that many of your news organizations are still able to have correspondents reporting freely in the heart of Benghazi is in itself testament to the immediate effect that this operation has had in blunting Colonel Gaddafi's assault on his own people.'

Last night David Cameron told MPs operations in Libya had 'helped avert a bloody massacre', before they voted 557 to 13 in favour of continued military action.